Expansion joint



Jan. 18, 1938. J. w. HELTZEL EXPANSION JOINT Filed April 1o, 1955 FIB J. W. HELTZE LIr FIB

.1. paf-'- EE EO Patented Jan. 18, 1938 UNITED STATES PATENT OFFICE Application April 10,

2 Claims.

The present invention relates to expansion joints for use in roadways of concrete and the like, and more particularly to certain improvements in the members of the joint and certain additions thereto.

An object of this invention is to provide an expansion joint which will more effectively transmit load pressure between adjacentislabs in the roadway.

Another object of the invention is to provide a pair of relatively movable expansion joint members with combined anchoring and guiding means for solidly holding the joint members to their respective slabs and for maintaining the members in proper alinement under load pressure and for relative movement as the joint expands and contracts.

A further object is to provide a joint of this character having expansion joint members which 2 are equal substantially to the depth of the road slabs to insure a solid joint and the maintenance of adjacent slabs at the same level, particularly under load carrying conditions.

Another object is to provide the expansion joint members with combined anchoring and guide bars so proportioned and mounted in the joint as to offset breaking of the slabs transversely across the road along the lines of the ends of the anchors.

With the foregoing and other objects in view, the invention will be more fully described hereinafter, and will be more particularly pointed out in the claims appended hereto.

In the drawing, wherein like symbols refer to like or corresponding parts throughout the several views,

Figure 1 is a top plan view of an expansion joint ready for insertion in a roadway, and showing the opposite side road sections connected together at the middle portion of the structure.

Figure 2 is an enlarged transverse section taken through the same substantially on the line 2-2 of Figure l, showing the adjacent road slabs molded about the joint.

Figure 3 is a similar view taken on the line 3--3 o-f Figure 1.

Figure 4 is a horizontal section taken longitudinally through the interiitting ends of the joint sections at the middle of the road.

Figure 5 is a horizontal section taken through the outer end of one of the joint sections, showing the closure plate at the end of the joint, and

Figure 6 is an enlarged transverse section similar to Figure 2, but showing a slight modification in the use of a sleeve for the sliding end of the anchor rod.

Referring now to the drawing, the expansion joint comprises an inner channel member which has its cavity facing outwardly away from 1935, Serial No. 15,713

(Cl. S34- 18) the joint to receive therein the adjacent portion of the road slab 2| to hold the inner channel member 2li rigidly on the slab 2l and for move'- ment therewith during the expansion and contraction of the slab. Slidablysupported on and enclosing the inner channel member 20 is an outer channel member 22 which is of similar construction and which is proportioned slightly greater than the inner channel member so as to freely and slidably receive the same. channel member 22 is molded into the opposite slab 23 of the roadway and is adapted to move therewith during the expansion and contraction of the slab 23. 22 are disposed in a vertical edgewise position in the road joint as shown in Figure 2 and the lower flange of the outer channel member 22 maybe flush with and rest upon the surface of the subgrade 24 of the roadway so as to support both of the channel members 20 and 22 in their vertical edgewise positions, and the widths of the channel members are sufficient to approach the upper surface portions of the slabs 2| and 23.

The outer channel member 22 carries a cap strip 25 which may be of cork, soft rubber or premolded asphaltic material secured by a suitable adhesive substance to the upper iiange of the outer member for holding the cap strip 25 in place vduring the molding and setting of the slabs 2l and 23.

The outer channel member 22 is provided at each end, as shown in Figure 5, with an end wall 26 which may be a portion of the channel meinber bent at right angles thereto in the direction of its iianges so as to overlap the opposite ends f of the inner channel member 2li and thus eiectively close the opposite ends of the space between the joint members. These joint members are constructed at their upper portions to conform substantially to the crown of the road and the lower portions of the joint members 20 and 22 are constructed to the configuration of the subgrade 24. The outer channel member 22 is also provided along its outer side with a shear bar 2l which may be suitably formed thereon or welded thereto and which is adapted for embedding in the adjacent road slab 23 to hold the outer channel member 22 against vertical displacement from its slab.

From Figures 1 and 4, it will be noted that a 5" stepped or scarf joint is provided at the meeting inner ends of the expansion joint sections.

In the present instance the outer channel member 22 of one section is longer at its inner end than the inner channel member 20 and the opposite expansion joint section is oppositely disposed with its outer channel member 22 of less length than its inner channel member 20, the distance in lengths being equal on both sections so that the desired overlap may be provided. This The The channel members 2D and split and overlapping joint is shown at 28 in Figures 1 and 4, and is provided merely to produce an expansion joint in two parts which are easily handled as against a single expansion joint structure of the full width of the road.

For the purpose of maintaining the relatively movable members 20 and 22 in alignment and also in assisting in the transfer of the load between the slabs 2| and 23 of the respective joint members, combined anchoring and gui-de pins are employed. As shown in the present instance the inner channel member 20, Figure 3, is provided with a plurality of anchor pir-is 29 which are in the form of rods disposed transversely through the member 20 and fixed thereto in any suitable manner, such; as by welding30. The anchor pins 29 are turned down at their outer ends as shown, or given any other suitable conguration to .effect anchorage, and are adapted to be embedded in .the adjacent road slab 2|.

. The pins 29 are of any suitable number spaced lengthwise throughout the inner channel member 2|] .and serve tohold the inner channel member 20 Aon the end of its slab 2|. Each anchor pin 29 extends through the member 2li and extends slidably through the opposite channel member 22 and slidably into the opposite slab 23 thus, the slab 23 with its outer channel member 22, may move toward and from the slab 2| with its channel member 20. The end of the anchor pin 29 which projects across the joint provides a guide pin 3| which may have a coating of heavy paint thereon, as shown in Figure 3, to insure the free sliding of the pin 3| in the slab 23. The outer channel-member 22 is provided, for each pin 3|, with. a bushing or bearing collar or boss 32 to take up wear about the opening through the channel member 22 and also to provide a substantial Surface bearing upon the pin 3|. This structure maintains the channel members 20 and 22 in substantially parallel relation throughout their movements toward and from each other.

As Shown in Figure 2, the outer channel member 22 is provided with anchor pins 33 which are given any suitable configuration to effect anchor age in the slab 23 and which projectthrough the two channel members, 22 and 2|), and are xed to the outer channel member 22 by welding 3|) as above described.

I'he inner 4channel member 20 is provided with openings therethrough and bosses or bearing rings 32 similar to the structure above described but in line with the anchor pins33, and the latter are provided with 'extensions forming guide and alining pins 34 which slidably engage through the channel member 20 and its slab V2|. The pins 34, like the pins 3|, may be provided with a heavy coating of paint or the like to insure slid- `rIhisvis to insure the firm mounting of the outer channel member on its slab 23 and also on account of the anges of the inner channel member 20 aording additional support for the inner channel member on the slab 2|, a lesser number of anchors 29 being required.

As shown in Figure 6, instead of coating the guide pins 3| and 34 with paint, slide tubes 35 may be embedded in the slabs for the respective guide pins, such as 34, and the guide tubes 35 may be welded or otherwise suitably secured to the adjacent channel member to substantially form a part thereof and admit of the free movement of the guide pins through the channel member and the tube 35.

From Figure 1, it will be noted that the guide p-ins 3| and 34 are of less length than are the anchors 29 and 33, so that at each side of the joint there is an uneven bracing or reinforcement in the slabs 2| and 23 to prevent possible breakage or cracking of the slabs along any definite transverse line.

In installing the joint in a roadway, the channel members 20 and 22 may be supported in upright position byl engagement of stakes or the like with the anchor pins 29 and 33 so as to hold the joint in position until the concrete or other material of the road is poured in against the oppositev sides of the joint.

What is claimed iszl. An expansion joint, comprising a pair of telescopic channel members nested one within the other for slidable interrelation and with the outer member larger than the inner member and with the flanges of both members extending in the Same direction, a cap strip mounted on the upper ange of the outer member, said outer member having a shear bar at its outer side for embedding in a road slab molded against the outer side O f the outer member to hold the latter from vertical displacement relatively to the slab, a plurality of anchor, pins Xed to the outer member and extending outwardly therefrom to hold the member to the road slab and extending inwardly therefrom for slidable engagement through the inner member and in the opposite slab thereof, said inner member having bearing openings therethrough for receiving the inner extensions of the anchor pins to maintain the members in alinement, a second plurality of anchor pins xed to the inner channel member and extending outwardly therefrom to hold the inner member to `an adjacent road slab moldedl against the outer side of the inner member and having inner ends extending slidably through the outer channel member and its slab, said outer channel member having bearing openings therethrough to receive the inner ends of the anchor pins of the inner member to maintain the members in alinement, said anchor pins extending irregular distances from the opposite sides of the channel members to prevent straight transverse lines of cracking in the molded road slabs.

2. In an expansion joint, a pair of intertting relatively slidable channel members, a plurality of transversely disposed anchor pins yextending through both of the memers with some of the pins secured to one channel member and having long ends extending to one side of said channel member and having short ends slidably engaging through the opposite channel member, and with the other pins secured to the opposite channel member and having long ends extending from the opposite side of the channel members and short ends slidable through said first channel member, whereby the ends of the anchor pins project irregular distances from the opposite sides of the channel members.

JOSEPH WILLIAM HELTZEL. 

